Surface-contact railway system.



No. 630,927. Patented Aug. l5, I899.

W. B. POTTER.

SURFACE CONTACT RAILWAY SYSTEM (Applica tion filed Mar. 16, 1898.) (No Model.)

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William BI otter, 9 ymfifiaw- NITED STATES PATENT OFFICE.

W'ILLIAM B. POTTER, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

SU RFACE-CONTACT RAILWAY SYSTEM.

SPECIFICATION forming part Of LGHZGIS Patent NO. 630,927, dated August 15, 1899.

Application filed March 16 1898. Serial N0. 674,014. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM B. POTTER, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Surface-Contact Railway Systems, (Case No. 656,) of which the following is a specification.

My invention relates to surface-contact railway systems, and has for its object to provide a time overlap for the switches which are actuated by current from the contactshoes, and this I attain by insuring the prompt closing of each switch in succession. When running at any considerable speed in systems in which the switch in advance of the one furnishing current to the car-motors is closed by a portion of the motor-current passing from one of the contact-shoes around its coil, in a way well understood in the art, it sometimes occurs that owing to the low resistance of the circuit through the shoe and the ground-oil cuit established through the switch already energized current goes to ground almost entirely through the last-named switch, while the switch in advance does not receive sufficient current to insure its moving with promptness, since it takes more current to close a switch than to hold it closed. To obviate this difficulty, I artificially increase the resistance of the contact-shoe which actuates the switches, so that the path of the current through the switch which has been actuated will have increased resistance relatively to the one which is about to be actuated, and thus the latter switch receives a larger share of the current and moves promptly. There are several ways in which the resistance in the circuit can be increased for the purpose described. The shoe may have an external or artificial resistanceconnected to it, the shoe itself being cut in two and the sections insulated, or its cross-section may be diminished at a point near its middle, or the whole shoe may be made of comparatively small section or of high-resistance metal, so that as it is drawn over the contact the resistance in the circuit of the closed switch steadily increases until the second contact touches the shoe.

The essence of my invention therefore consists more in the method of operation outlined than in the apparatus, though there is material novelty in that also, the method consisting in closing the switch with a certain current, then increasing the resistance of the circuit of the closed switch, so as to compel the current to seek the path through the coil of the switch which is about to close, then after that switch closes cutting down its current by the added resistance, and so on.

The accompanying drawings show ways of carrying out my invention.

.Figure 1 shows in diagram the system now well known to which it is to be applied, and Fig. 2 illustrates different ways of carrying out its purposes. 7

In Fig. 1',A A are the track-rails; B,the highpotential or positive studs or contacts; O, the negative or low-potential studs or contacts; D D, the wheels of the car 5 E, the storage battery; S, a switch by which the battery may be thrown into or out of circuit, and RS a reversing-switch for reversing the motor M. All of these parts are well known.

H is a feeder supplying current to operate the road.

G G are switches by which successive connection between the studs B and the feeder is effected. These switches are provided with contacts g g g and an operating-coil G connected between the contacts or studs 0 and ground.

F F are the contact-shoes.

So far the parts are of ordinary construction and operate as follows: At starting the switch S is thrown and current passes from the storage batteryE directly to the shoe F, thence by contact G, upon which the shoe rests, through the coil G to ground, closing the switch G. From ground current passes back to the battery E, one end of which is grounded on the car-wheel D Current then passes from the feeder H, by contacts g, &c., to the positive studs B 13, upon which the shoe F rests, and thence through the field and armature of the motor M, The switch S may be then opened and current from the motor-circuit will energize the switches G in succession as the shoe F touches each of the contacts O, the main motor-current passing to ground through these contacts in multiple.

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At this point the operation of my invention begins. The shoe F is divided into two parts f f between which is connected the resistance R, a section I of insulating material being placed between the parts of the shoe. As soon as the shoe F touches the contact 0 next the one upon which it is resting a great part of the motor-current will pass to ground through this contact on account of the interpolation of the resistance R. Sufficient current, however, will still pass the resistance to hold the switch G closed, it being well known that it takes more current to effect the closing of the switch than it does to hold it closed on account of the diminution of the air-gap when the switch is closed.

To get the full advantage of myinvention, the current should enter the shoe at its front end. I therefore provide a switch K, preferably connected to the reversing-switch RS, so that the two are thrown together. Thus whenever the direction of motion of the car is reversed the switch K is also operated to connect the front end of the shoe to the source of currenteither the batteryE or the negative terminal of the motors, as the case may be. Both the switch S and the switches RS and K may be placed on the car-controller, as will be obvious to one skilled in the art.

In Fig. 2 I illustrate three several forms of contact-shoe, to which I have adverted in the statement of invention. The first of these shows in diagram the resistance connected in between the parts ff of the shoe F, while in the second form a part f of diminished section answers the same purpose. In the third form shown the shoe itself is formed of smaller section or of some resistance material, or both. Other arrangements will of course readily suggest themselves.

That I claim as new, and desire to secure by Letters Patent of the United States, is-

1. The method described of insuring the successive closing of a number of electricallyoperated switches, which consists in increasing the resistance in the circuit of a switch already closed, and thus increasing the current in the switch about to close.

2. The method described of insuring the prompt closing of the successive switches in a surface-contact railway system, which consists in closing a switch at full current, and

' increasing the resistance in the circuit of the switch until the shoe makes contact with the switch in advance of the one already closed, thereby diverting to that switch the greater part of the current, and insuring its closing.

3. The method described of operating in sequence a nu mber of electromagnetic switches, which consists in closing each switch with full current, gradually diminishing the cur rent in that switch until about the time of closing the next switch in advance, and then breaking the circuit, as set forth.

at. The combination with a number of electromagnetically-operated switches, and a contact device furnishing current to close the switches in succession, of means for increasing the resistance in the circuit of each switch after its closure.

5. In a surface-contact railway system, a number of electromagnetically operated switches, a contact device taking current at its forward end in either direction of movement, and means for increasing the resistance in the circuit of the contact device af ter each switch is operated.

6. In a surface-contact railway system, a number of electromagnetically-operated switches to be closed in succession, a contactshoe, a resistance in the circuit of the contactshoe, and a switch for connecting the forward end of the contact-shoe in either direc tion of movement to the source of current by which the switches are actuated.

7. In a surface-contact railway system, a contact-shoe carried by a moving vehicle, a reversing-switch, and a switch for connecting the front end of the shoe in either direction of movement with the source of current, the two switches being combined in one or hav ing a connection by which they are simu1ta= neously operated.

8-. The method of closing a series of electro magnetic switches successively, which consists in connecting one switch with a source of electricity, inserting a resistance between said switch and the source, and connecting the next switch to the circuit between said resistance and the source.

9. The method of supplying electricity continuously from a sectional conductor to an electric vehicle, which consists in closing the circuit through an electromagnetic switch, inserting a resistance between said switch and the source of current, connecting the next switch to the circuit between said resistance and the source, and then opening the circuit through the first switch.

10. The method of operating a series of electromagnetic switches, which consists in connecting a switch with a source of electricity, gradually increasing the resistance of said switch-circuit, and connecting the next switch to the circuit between said resistance and the source.

11. The combination with a series of electromagnetic switches, of acontact device having a part reduced in cross-section, said device being adapted to close the circuit through the switches successively.

12. The combination with a series of electromagnetic switches, of a contact device adapted to close the circuit through the switches successively, and means for gradually inserting resistance in each switch-circuit after its closure.

13. The combination with a series of electromagnetic switches, of a contact device adapted to close the circuit through the switches successively, and means for diverting the greater part of the current flowing through a switch after its closure into the next succeeding switch.

14. The method of operating a series of elec- T circuit, and a second electromagnetic switch trornagnetic switches, which consists in closadapted to be connected with said contact ing the circuit through one switch, and then device between said resistance and the source diverting the greater part of the current flowof current.

5 ing through said switch into the next sncceed- In witness whereof I have hereunto set my [5 ing switch. hand this 14th day of March, 1898.

15. The combination with an electrolnag- WILLIAM B.- POTTER; netic switch, of a traveling contact device Vitnesses: adapted to supply current to close said switch, B. B. HULL, 10 means for inserting resistance in said switch- J. L. D. LANGDON. 

